269739 Thermocatalytic Conversion of Pongamia Pinnata Seed Cake Over Ruthenium Impregnated MCM-22 Catalyst

Tuesday, October 30, 2012: 4:55 PM
303 (Convention Center )
Dinesh Singh, Chemical Engg., I.P Uelhiniversity , Delhi, India and K. K. Pant, Chemical Engineering Department, Indian Institute of Technology, Delhi, New Delhi, India

Thermocatalytic conversion of  pongamia pinnata seed cake over  ruthenium impregnated MCM-22 catalyst

 

This work studies the pyrolysis of pongamia pinnata seed cake for the production of bio oil. India is fast growing economy with over 120 billion people and facing the challenges to meet the  need of energy demand. Production of energy crops like jatropha and pongamia pinnata for the production of biodiesel is already a national policy. It is assumed that that seed cake generated after oil extraction will be huge and its disposal thus may be a problem. Direct burning of this cake will not be a beneficial option. Energy generated by burning of this biomass is very low 15-16 Mj/kg. As it is not possible to extract all oil from these seeds so it is expected that these seeds with cellulose, hemicelluloses and lignin will also have some oil components. Pyrolysis is a process wherein we heat biomass in absence of oxygen and the complex molecules of biomass defragment into to smaller carbon number hydrocarbons mostly in the range of C1 to C44. In thermal pyrolysis we mainly get either light gases like CO, CO2, methane or   either very heavy molecules leading to formation of tar both of these hydrocarbon not consider good as transportation grade fuel. Besides this another major factor which hinders the use of thermal pyrolysis for the production of bio oil is the oxygen content which decreases the calorific value of the bio oil. Hence our focus is to reduce the oxygen content as well as crack the molecules in the range of   diesel fuel.   Research has been done on the cracking of pyro oil using ZSM-5 as catalyst impregnated with nobel metals. In this work we have used Ru supported over MCM-22 as  catalyst for the cracking of biooil. MCM22. MCM22 has large pore diameter formed by 12 member rings with a system of 10 member rings. These large pore allows large hydrocarbon molecules to enter in the cage structure and thus provide more catalytic surface area for cracking reaction to occur.  Ru-supported catalysts were prepared using conventional wet impregnation technique. An appropriate amount of precursor solution of RuCl3-xH2O, was dropped to the MCM-22 to obtain desired wt% of Ru, followed by drying in an oven at 110 oC for 3 h. The catalyst was calcined from room temperature to 580 oC. Prior to catalytic activity testing, all catalysts were reduced by hydrogen at 400 oC for 3 h. The catalyst was characterized using SEM, XRD, BET and chemisorptions. Oil extracted Pongammia pinnata seed cake has been utilized for the production of bio oil in a fixed bed SS 316 reactor under atmospheric pressure using a semibatch operation. In a typical process two zones were prepared in the reactor, one of biomass with typical mass of around 10 g whereas the weight of catalyst was varied from 1 to 3 grams. Nitrogen gas flow rate was varied from 25 ml/min to 100 ml/min which provide an inert atmosphere as well as swept the volatile products from the reactor to the condenser.  The uncondensed gases were analyzed by GC TCD for CO, CO2, H2 and methane whereas higher carbon number gases were analyzed by FID  Porapak Q packed column. The liquid products were analyzed by capillary column of ZB-1. Prior to liquid analysis bio oil was dissolved in carbon disulphide and was given 30 minutes ultrasonic treatment. The effect of temperature, nitrogen gas flow rate and biomass to catalysis weight has been studied. The pyrolysis products were further passed through condenser so as to separate condensable and non condensable as liquids. Further condensed vapors were separated as aqueous phase and oil phase. Pyrolytic oil obtained were analysed by GC, NMR and FTIR. Gas chromatograph mass spectrometry (GC–MS, PerkinElmer clams 500) equipped with a HP-5 capillary column (30 m x 0.25 m i.d., 0.25 mm film thickness) was used for identifying the compounds in the liquid sample. Helium (99.999%) was used as the carrier gas with a constant flow rate of 1 mL/min. in split less mode. The oven temperature was programmed from 35oC to 100oC in 2 minutes, 100oC to 200 oC 5 in minutes and 200oC to 250oC up to 30 minutes. MS was conducted with the following operation conditions: transfer line 250oC, ion source 150 oC and electron energy 70 eV. Bio oil and higher carbon number gases were analyzed by using a combination of packed and capillary column. Thermogravemetric analysis of the seed cake were also performed with different heating rate (2, 5, 10 oC/min ) in nitrogen atmosphere prior to the pyrolysis to find out the initial and final temperature for thermal degradation. The solvent extractives, cellulose and lignin content were analyzed using TAPPI standards e.g.  T204 cm 97, T203 cm-99 and T236 cm-85 respectively. SEM analysis of biochar was done to see the effect on the change of structure of biomass before and after pyrolysis. The 1H NMR (Proton nuclear magnetic resonance) spectrum of the bio-oil was recorded using a Bruker, 300 MHz High Performance Digital NMR Instruments. The samples were dissolved in deuterated chloroform containing TMS (Tetramethylsilane) as a standard. Bio oil and upgrade bio oil with ruthenium as noble metal shows 1H-NMR spectra with different peaks. These peaks can be divided into three main regions: aromatic, olefinic, and aliphatic, based on the chemical shifts of specific proton types in the regions of 9.0–6.0, 6.0–4.0, and 3.0–0.5 ppm, respectively. FTIR analysis was done using KBr pellets. The bends near the 3350 shows the presence of O-H group whereas those near to 3100 confirm the presence of aromatic rings. Large spectra beyond 3400 indicate presence of water and that of near to 2500 arise due to the presence of paraffinic compounds. Peaks near around 1700 confirms C=O group. GCMS analysis confirms the presence of few of the components octadecanoic acid, pentadecanenitrite, 9 nonadecene, hexatricontane, Pnonyloxybenzaldehyde, 2(4 hydroxybutyl_-2 nitro cycloecanone. TCD data confirms that an increase in the pyrolysis temperature leads to higher production of hydrogen and methane where as lower temperature that is up to 400oC yields more of CO and CO2. Also it was observed that though there is not much change in the char yield with or without ruthenium but a small increase can be seen in the gas yield in presence of ruthenium. At the same time, all the oil obtained in presence of ruthenium shows a shift towards the increase of lower hydrocarbons (between C6 to C20).   Furthermore it was observed that an optimum of 1% ruthenium leads to highest yield (~45.3%) of bio oil with carbon number from C-9 to C18 (boiling point cut 80-320 oC).


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